Merge pull request neetcode-gh#103 from ediazmen/Exercise-125

JS 125-Valid-Palindrome

Author: neetcode-gh

javascript/125-Valid-Palindrome.js

@@ -16,4 +16,4 @@ var isPalindrome = function(s) {
         j--
     }
     return true;
-};
+}; 

javascript/125-ValidPalindrome.js

@@ -0,0 +1,30 @@
+class isValidPalindrome {
+    constructor(string){
+        this.string=string;
+    }
+    isPalindrome(string){
+        let left =0;
+        let right=string.length-1;
+        while(left<right){
+            while(left<right && this.isAlphaNumeric(string[left])){
+                left++
+            }
+            while(right>left && this.isAlphaNumeric(string[right])){
+                right--
+            }
+            if(string[left].toLowerCase()!=string[right].toLowerCase()) {
+                return false;
+            }
+            left++
+            right--  
+        }
+        return true
+    }
+
+    isAlphaNumeric(c){
+        return ('A'.charCodeAt(0) <= c.charCodeAt(0) <='Z'.charCodeAt(0) || 
+                'a'.charCodeAt(0) <= c.charCodeAt(0) <='z'.charCodeAt(0) ||
+                '0'.charCodeAt(0) <= c.charCodeAt(0) <='9'.charCodeAt(0))
+    }
+    
+}